(1) Field of the Invention
This invention relates to a process and an apparatus for cutting and removing automatically only the flaw portion of a wire material and a rod-like material by use of a centerless peeling machine for the automatic cutting and removal of the surface flaws of these materials having the construction wherein the cutting tool is allowed to advance and retreat freely.
(2) Description of the Prior Art
In producing specific bar steel and a stainless steel, or a wire product, a blank material is subjected to the hot rolling treatment and then converted into a coil after its surface flaws are sufficiently removed, as is well known in the art. However, flaws having a maximum depth of about 0.3 mm are partially scattered on the surface of the coil, and the following steps have been employed conventionally in order to remove these flaws to feed the material to the subsequent machining stage;
(1) The blank material is stripped off over its entire length and thus peeled by use of a tipper die;
(2) The blank material is cut and peeled by a centerless peeling machine; and
(3) Flaws are detected by visual observation and only the flaw portions are ground and peeled by a hand grinder, etc.
In the methods (1) and (2), however, the blank material is frequently peeled even into the flawless portion so that lowering of the yield of product, quick consumption of peeling tools and increase in the cost are remarkable, while in the method (3), peeling is effected only to the necessary portion so that the yield of product can be improved to a marked extent. However, this method is not free from the problem of extremely poor working property because a cold coil is first released and flaws on the outer circumference of a wire or rod material are then detected by the visual check to require grinding each time flaws are found. Hence, this method is not satisfactorily efficient and results in the disadvantage of a drastic increase in the labor cost.
The present invention solves these problems of the conventional surface flaw removal and enables one to restrict the increase in the labor cost, to improve the yield of product, to materialize high efficiency due to shortening of cutting time and thus to ensure reduction of the overall cost by cutting automatically on the flaw portion(s) of the blank material. By the use of a centerless peeling machine which is capable of advancing and retreating to and from the material to be machined, the present invention enables one control automatically a sequence of cutting works including the detection of flaws, advancing and retreating actions of the cutting tool most suitable for the conditions of the flaws so detected and the suitable travelling speed of the material to be machined.